Sulfinates palladium complexes

A number of other iridium, ruthenium, platinum, and palladium complexes were investigated, but highest yields were obtained with the rhodium complex. The de-sulfonylaiion is believed to proceed by formation of a metal sulfinate complex and loss of SO2. 

Uozumi and coworkers prepared phosphine/palladium complexes supported on polyethylene glycol-polystyrene graft polymer. - This amphiphilic resin-supported palladium complex eftidently catalyzed the alkylation of allylic acetates in water with various nucleophiles including 1,3-dicarbonyl compounds, amino acids, sodium azide, sodium sulfinate, phenylboronic acid, and sodium tetraphenylborate to give the corresponding allylic-substituted products in quantitative yields. 

Herwig, J. Keim, W. (1994) Palladium complex-catalyzed synthesis of sulfinic acids, sulfinic acid-esters, sulfonic-acids and 5-alkyl alkanethiosulfonates, Inorg. Chim. Acta, 222,381-5. 

Alkyl halides or alkyl sulfates, treated with the salts of sulfinic acids, give sulfones. A palladium catalyzed reaction with a chiral complexing agent led to sulfones with modest asymmetric induction. Alkyl sulfinates (R SO—OR) may be side products. Sulfonic acids themselves can be used, if DBU (p. 1337) is... 

Compound la is prepared by reacting bis(benzonitrile)palladium chloride with butadiene in benzeneTHF or acetone - at RT. In methanol, the methoxy complex Ib is formed instead ", and in acetic acid the acetate Ic is produced . Additional examples of nucleophiles are sulfinates and amines. The E groups are readily displaced e.g., CH3O, acetate and (CH3)2N can be rapidly displaced in the presence of catalytic amounts of acid. 

An efficient method for palladium(II) catalytic desulfitative conjugate addition of arylsulfinic acids with a, -unsaturated carbonyl compound has been developed. Experimental evidences for the key reacting intermediates including aryl Pd(II) sulfinic intermediate, aryl Pd(II), and C=0-Pd complexes were provided. The mechanism of the dehydrosulfenylation of 2-arylsulfinyl esters for furnishing enoates has been determined to be a homolytic process. The interception of the radical intermediate using a nitroxyl radical and mass spectrometry techniques were useful for identification of the intermediates involved in the dehydrosulfenylation of 2-arylsulfinyl esters. These data indicated that a radical-mediated process is operative. Tetrabutylammonium iodide has been found to promote deselenylation reaction of ) -chloro- and -oxyselenides to afford alkenes efficiently with formation of selenenyl iodides. A catalytic version of the transformation has also been developed. 

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